Adolescent marriage and childbearing remain widespread in northern part of Nigeria despite various
efforts by governments and non-governmental organizations to discourage the practice. Motivations for
adolescent marriage, pregnancy, childbearing and family size remain poorly understood. Hence, this research
article investigated adolescent motivations for marriage, pregnancy, childbearing and family size in North-
Western Nigeria. A community-based and cross-sectional research design was adopted. Primary data were
obtained using quantitative methods. A survey of 1,175 adolescents aged 12-19 years was carried out, using
multi-stage sampling techniques involving states, Local Government Areas (LGAs), towns/villages, main
streets, houses, households and individuals. Frequency distribution, multiple classification, chi-square, and
regression analyses were used for data analysis. The results show that motivations for teenage marriage and
childbearing reflect various level of influence, such as parental pressure, and socio-economic status, social
norms, as well as individual needs and desires. About 45% of the adolescents desired large family size of six
children or more; more male adolescents (48.3%) than female (43.8%) desired large family size. Adolescentsí
gender, residence, ethnic origin, religion, educational level, knowledge and approval of contraceptive methods
were significantly associated with family size preferences (p<0.05). The likelihood of large family size
preference is significantly higher among adolescents whose parents had no formal education, married as
teenagers, had six children or more, and practiced polygyny. Essentially, social and economic circumstances
of adolescents and their parents are crucial motivations for teenage marriage and childbearing, as well as fam ily
size preference in North-Western Nigeria.